Glyn Moody writes: At a recent Open Hardware Camp in London, it became clear that one of the main obstacles to applying open source principles to hardware was licensing. For example, should competing big companies be allowed to use their economies of scale to make and sell cheaper products based on open hardware designs developed by small start-ups without payment? There's also the problem that hacking designs for physical objects like open source cars may have safety implications, which raises questions about liability. So what's the best way to address these issues?